Summary: | 碩士 === 國立屏東科技大學 === 獸醫學系 === 88 === The purpose of this study was to idenitify Ehrlichia species in dogs and cats in Taiwan, and to establish a quick and accurate laboratory diagnostic method to assist diagnosis and control of this particular disease in dogs and cats. We collected canine and feline blood samples randomly from clinically cases at Department of Teaching Animal Hospital, National Pingtung University of Science and Technology, and feline blood samples from clinical healthy cats in Kaohsiung city in June, 1999 to March, 2000. The samples were used to develop PCR diagnostic technique for detecting Ehrlichia species, and to compare results among PCR test, IFA test and blood smear examination based on value of clinical application. The results: 110 dogs and 17 cats were amplified with nested PCR by EC1 to 4 primers. Twenty-two out of 110 dogs (20%) and two out of 17 cats (11.76%) assumed positive. Fifty-four dogs were amplified with nested PCR by EE1 to 4 primers. Two out of 56 dogs (3.57%) assumed positive. The former products were sequenced and collated with standard strain (M73221) by DNASTART software, and confirmed that all of them were E. canis. The sequence similarities of 16S rDNA genes among them were above 97%. Results of IFA test showed 40% of dogs (24/60) were IFA test positive, 60% of dogs (36/60) were IFA test negative. All of these cats were IFA negative. Ehrlichial inclusion was not seen in peripheral lymphocytes of all cats. Ehrlichial morulae in peripheral blood cells were found in 5 of 17 cases of PCR positive dogs. The percentage of peripheral lymphocytes containing elementary bodies (EB) and/or initial bodies (IB) less than 20% was found in 93.94% (62/66) of PCR negative dogs; and the absolute number of similar lymphocytes less than 600/ml was found in 95.52% (64/66) of PCR negative dogs. It is, thus, from the present paper, suggested that the number of peripheral lymphocytes containing EB and/or IB, ignored previously, could be clinically used as evidence of ehrlichial infection in dogs. It was also found, from the present study, that sensitivity was highest in IFA test, moderate in PCR test and lowest in presence of morula in blood smear examination; while specificity was highest in PCR test, moderate in IFA test and lowest in blood smear examination for detection of canine and feline ehrlichiosis using blood as test sample. Besides, occurrence of infection of E. canis in cats found the present paper is the first case report in Taiwan.
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